Lynch-related endometrial cancer raises risk of other cancers

Women with Lynch syndrome who have been diagnosed with endometrial cancer have elevated risk for several other cancers, including breast, bladder, and kidney cancers, according to a recent analysis.

“This new information…helps us counsel women with Lynch syndrome who have had endometrial cancer about the magnitude of their future cancer risk, which turns out to be about 55% over the 20 years after diagnosis of their endometrial cancer,” explained study coauthor Dennis J. Ahnen, MD, of the University of Colorado Cancer Center in Denver, in a statement issued by University of Colorado Denver. “It [also] helps fill in the picture of the spectrum of cancers that are associated with Lynch syndrome, which includes not only colorectal and endometrial cancers, but kidney, ureter, renal, pelvic, urinary, bladder, and breast cancers.”

In the study, reported in Journal of the National Cancer Institute, Ahnen and fellow investigators in the United States, Canada, Australia, and New Zealand reviewed data from the Colon Cancer Family Registry for a cohort of 127 women who had been diagnosed with endometrial cancer and who carried a mutation in one of four DNA mismatch repair (MMR) genes. (Lynch syndrome is an inherited disorder caused by mutations in MMR genes, and MMR gene mutation carriers have been shown to be at increased risk for colorectal, endometrial, and several other cancers following an initial diagnosis of colorectal cancer.)

The data revealed that following Lynch-associated endometrial cancer, women had an 11% lifetime risk for breast cancer, which was 2.51 times higher than the risk for women outside of this population. Compared with the general population, the women with Lynch syndrome and a diagnosis of endometrial cancer were also at statistically significant elevated risks of cancers of the kidney, renal pelvis, ureter, and urinary bladder.

Women with Lynch-associated endometrial cancer were also at greater risk for colorectal cancer. However, that risk was calculated to be lower than previously estimated. "This cross-section shows a 50% to 60% lifetime risk of developing colorectal cancer in people with Lynch syndrome, as opposed to earlier estimates of 70% to 80%," clarified Ahnen.